Gardening with Gary




Gardening Advice from an Expert

Snowball Bushes

Member Betty writes~
I have had a "snowball bush" for 4 years. It bloomed the first year only. Some of the tips of the leaves are turning brown. What can I do to get it to bloom?

A. There is a Common Snowball (Viburnum opulus 'Roseum') and a Japanese Snowball (Viburnum plicatum) Bush. Japanese Snowball grows 7 to 12 feet tall with maple-like lobed leaves 3 1/2 inches wide. Common Snowball Bush is the most common that grows 6-10 feet tall.

What is the general health of the plant? You might want to check the soil fertility and pH, soil type, and water/sun situation. I suspect not enough water in hot weather and more fertilizer needed. A pH test kit is easily available at a garden center. Make sure than the soil is properly drained, irrigated and there is enough phosphorus [look for a high middle number on the label] for flowering. They do need some help, after all!

The snowball bush does not require more than a soaking once a week -- perhaps 5 gallons applied slowly, says University of California master gardener Bill Pierce. Too much or two little water can influence flowering. It tolerates alkaline or acid soils and grows in part shade to full sun. Snowball bush is a spring bloomer; therefore, it is critical to prune at the correct time. Fall or winter pruning will remove flower buds. Prune only after bloom has finished. The bush is subject to aphids, thrips, spider mites and scale. Any of these infestations could cause bloom failure. Most of these pests can be eradicated with a strong blast of water applied daily for 3 or 4 days. Your plant may be perfectly healthy and just needs more time to become established before it will bloom more.

If you have a cooperative extension agency or a nearby university with a horticultural department, you might bring a branch in to them for further evaluation, but the brown edging sounds like lack of water.

You just must check out this picture I found of one. The name there is misspelled, as it is a Viburnum opulus, your plant:

www.members. tripod.com/~freelunch/snowball.htm

M.M. writes~ I have a snowball bush or tree whatever they call it. It does not bloom anymore. Are they supposed to be pruned? Is there a natural way to kill weeds?



A. Snowball bush is applied to several plants, the Japanese, Chinese and European Snowballs, which are all Viburnum varieties. Japanese and Chinese Snowballs bloom in spring and their flowers often remain for up to three weeks. European Snowball, an old fashioned variety, is subject to attacks of disfiguring plant lice so is not as desirable.

In general, spring flowering plants bloom from buds formed the previous season. Any serious pruning is done just after flowering, so the plant can set buds for the following year. Sometimes a little light trimming can be done during the dormant season. Most viburnums don't need much pruning. When they get overgrown and need thinning, the oldest trunks can be cut off at the ground, and the younger, more vigorous shoots left to grow on. Most are big shrubs. When they get too large, they sometimes need to be cut back, although this may destroy the graceful shape of the shrub. Occasionally, when shrubs get too tangled and overgrown, they can be renewed by being completely cut back to the ground in spring (after enjoying the flowers) and fertilizer is spread around them on the ground. Sometimes they take two or three years to bloom well again. The English often renew their shrubs in this manner.

Expert advice: www.BobVila.com

As far as a natural herbicide against garden weeds, I have composed a list which will be up shortly at my site, GardeningWithGary.

Lero writes~ Is there a way to root a snowball bush? I've been trying with no success.



A. I tried this method to propagate Annabelle hydrangeas and a few other hardwood branches. It may work for your snowball better than cutting off a flower bud and placing it in a soil mix. Make a small nick in the underside of one lower branch. Weigh down the branch so that the nicked branch is on the ground. Cover that portion of branch with compost and light soil and allow to root. Keep evenly moist, but not water-log, or the stem will rot. Protect from any strong sunlight.

Next spring, you should see that your branch has set roots and you will have a new baby snowball sapling which you may cut loose from the main plant and transplant elsewhere.

Michelle writes~
I have Snowballs and Hydrangeas growing together beside my house. They have been there for several years now and are doing well. They all exploded this spring/summer due to all the rain we have gotten here in the sunny south. The only problem I am having is that my Snowballs have never blossomed! They have been in the same spot and growing well for about 5 years now and are quite large. This year they put out lots of red berries that showed up in early summer. The berries are just now starting to wither, but still no flowers. What is going on? Is there anything I can do to help?



A. I immediately suspect the pH of the soil. Please take several soil samples to a depth of 6" and bag it. Take to your local agriculture inspection or cooperate extension service. Check your phone book or call a local college. I predict your soil pH is too high, being alkaline and not acidic. Other shrubs needing low pH are azaleas, rhodies, camellias and gardenias to mention but a few.

Viburnum is one of the largest and most important groups of garden shrubs. There are over 150 species; some are evergreen, others deciduous. White flowers in early summer followed by red to black fruit in autumn, is the norm. Many of the deciduous species have spectacular fall color. Although they do not require acidic soil, they will grow and flower quite favorably under acidic-soil conditions.

Terry writes~ We planted snowball bushes in 1996. They are 12' or higher, always very beautiful every year. This year was no different until we got 28 out of 30 rain days. We have six of them and noticed that the leaves have little holes all over and then lost all the leaves and these bushes are bare. Is there something I can do to bring it back to life? I do not want to lose them. They are so beautiful.

A. Snowballs [Viburnum] have a medium tolerance to overly wet soil. On the whole, how well landscape plants tolerate excessive moisture varies greatly from species to species and the soil growing in. Clay is very heavy and holds water longer than sandy loam. Another consideration is the age and general health of a plant before having to deal with the water and the conditions these stressed plants are exposed to once the water abates. So, with all these factors working together, predicting how a plant will be affected is somewhat of a guessing game. Plants need to grow in soil that has room for air between the particles of soil; otherwise they can literally drown. If their roots cannot breathe, they die of lack of oxygen. Working leaves give off oxygen as a waste product and roots use oxygen. When soil is waterlogged, roots and soil organisms use all available oxygen, giving off carbon dioxide. If the situation persists, some minerals in the soil are changed into soluble forms that are toxic. Various other substances begin to build to toxic levels, too. In addition to affecting the root system of plants, excessive moisture leads to a number of foliage diseases caused by fungi that thrive in humid conditions. Take a few leaves to your Ag inspection agency to see if a fungicide should be applied to the remaining leaves. In some cases, a plant dies immediately after the excess water is gone because it can no longer absorb the water that is available. Roots can also be so damaged that decay sets in. When soil has been saturated for very long, many of the necessary microorganisms that help create a hospitable environment for plant roots are wiped out. When this happens, plants tend to be more susceptible to fungal diseases. This is because roots have been damaged and because the excess water physically spreads disease pathogens throughout the soil It may be months before a plant regains its natural resistance. Some plants are so susceptible that they can go from healthy to dead in a matter of days. Others can take waterlogged soil for weeks without exhibiting any symptoms. If the plants are established and were healthy when the excessive water started, they will probably be fine. One must wait and see. Hopefully, if it does continue to rain, there will be a couple drying days for the plants to breathe.

Assistance from: Mary Henry and Margaret Purcell, Horticulturists http://www.bachmans.com